Abstract:
Discrete element models are widely used in the analysis of masonry
structures, as they provide an effective approximation of the observed
behaviour, namely for modelling collapse modes governed by the
discontinuities. Assessment of the response under earthquakes is an important
application of these models, which perform time domain dynamic analysis
using explicit algorithms. Rayleigh damping is generally used, but its
mass-proportional component has potential adverse effects, and the small steps
required by explicit solutions lead to large computational costs. An alternative
damping formulation employing Maxwell elements in parallel with the joint
stiffness is proposed and tested. Problems involving linear elastic analysis of
column bending, rocking of rigid blocks, and out-of-plane failure of masonry
walls under seismic loading are examined. The proposed damping approach
displayed a sound mechanical performance and is computationally efficient.
These early results justify further investigation of the technique for a broader
application in masonry structural dynamics.